Reaction of C-60 with oxygen initiated by radicals from azo(bisisobutyronitrile)

In an o-dichlorobenzene solution exposed to an atmosphere of air or pure oxygen, C-60 reacts with radicals generated by thermal decomposition of azo(bisisobutyronitrile) and with oxygen to form mixtures of highly substituted and oxygenated monomeric, dimeric, and trimeric derivatives. LSIMS, LDMS, and SIMS (Liquid Secondary Ion, Laser Desorption, and Secondary Ion Mass Spectrometry) of these mixtures give clusters of peaks for C-2n from C-40 to greater than C-200. Elemental analyses show large H, N, and O contents that increase with the amount of AIBN and the partial pressure of oxygen during the reaction. H-1 and C-13 NMR spectra consist of broad bands assigned to complex mixtures of substituted fullerenes containing many 2-cyano-2-propyl groups derived from AIBN. Diffuse reflectance infrared spectra show hydroxyl and carbonyl functional groups. Thermal gravimetric analysis (TGA) of the mixture prepared under oxygen retained 40% of the initial weight at 640 degrees C, while <19% of the initial weight remained from the mixture prepared under argon.